Thomas, you could try https://github.com/mangledjambon/drumbooth to separate sinusoidal and impulse-like parts of sounds, and then do your additive analysis on the sinusoidal part only. The deconstruction is based on Derry FitzGerald HARMONIC/PERCUSSIVE SEPARATION USING MEDIAN FILTERING, Proc. of the 13th Int. Conference on Digital Audio Effects (DAFx-10), Graz, Austria , September 6-10, 2010, http://dafx10.iem.at/papers/DerryFitzGerald_DAFx10_P15.pdf .
-olli On Thu, Jul 27, 2017 at 3:08 AM, robert bristow-johnson < r...@audioimagination.com> wrote: > > > > > Thomas, are you recording single isolated drum hits that you analyze? or > are you trying to lift this partial information from a drum track with many > hits? > > if the latter, you'll need to do a transient detection which should be > pretty easy with monophonic drum hits. if the former, then you just need > to trim off the silence preceding the onset of the hit. and the > Levine/Smith model is good, but you can probably do it most easily on > isolated drum hits even without much reference. > > then you want a window (or a half-window, like the latter half of a Hann > window) to capture the attack transient and window down to zero at the > "steady-state". if there are no snare wires or beads, then i don't think > there should be much of a noise component after the initial transient that > you window off. so what is left after the transient should be a collection > of decaying sinusoidal partials > > since it's a drum and not a string or horn, the partials are not likely > harmonic. so then you need to use well-overlapped windowed frames and FFT > it. for analysis, the windows need not be a Hann or Hamming or some > complementary window. for analysis, i would recommend Gaussian windows > because each partial will have it's own gaussian bump in the frequency > domain and there should be very little sidelobe behavior between partials. > the frequency and amplitude of the partial should be the horizontal > location and height of the interpolated peak of each gaussian bump in the > frequency domain. remember the phase for a particular partial of a frame > should be the phase of the same partial in the previous frame plus the > (angular) frequency times the elapsed time between frames. that should > help confirm tracking of the partial to make sure you're connecting each > partial to it's counterpart in the previous frame. if you're careful, the > envelopes should be smooth and mostly monotonically decreasing in amplitude. > > then synthesize with basic sinusoidal additive synthesis, adding to the > windowed attack. > > good luck. > > r b-j > > > > > Sinusoidal-only modeling could be limiting for some of the intrinsic > > features of percussive sounds. > > A possibility would be to encode partials + noise (Serra and Smith, 89) > > or partials + noise + transients (Levine and Smith, 98). > > > > > > > > On 7/26/2017 4:37 PM, Thomas Rehaag wrote: > >> > >> can anybody tell me how to track drum partials? Is it even possible? > >> What I'd like to have are the frequency & amplitude envelopes of the > >> partials so that I can rebuild the drum sounds with additive synthesis. > >> > >> I've tried it with heavily overlapping FFTs and then building tracks > >> from the peaks. > >> Feeding the results into the synthesis (~60 generators) brought > >> halfway acceptable sounds. Of course after playing with FFT- and > >> overlapping step sizes for a while. > >> > >> But those envelopes were strange and it was very frustrating to see > >> the results when I analyzed a synthesized sound containing some simple > >> sine sweeps this way. > >> Got a good result for the loudest sweep. But the rest was scattered in > >> short signals with strange frequencies. > >> > >> Large FFTs have got the resolution to separate the partials but a bad > >> resolution in time so you don't even see the higher partials which are > >> gone within a short part of the buffer. > >> With small FFTs every bin is crowded with some partials. And every > >> kind of mask adds the more artifacts the smaller the FFT is. > >> > >> Also tried BP filter banks. Even worse! > >> It's always resolution in time and frequency fighting each other too > >> much for this subject. > >> > > > -- > > > > > r b-j r...@audioimagination.com > > > > > "Imagination is more important than knowledge." > > _______________________________________________ > dupswapdrop: music-dsp mailing list > music-dsp@music.columbia.edu > https://lists.columbia.edu/mailman/listinfo/music-dsp >
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